Miniature missile system

ABSTRACT

A miniature missile system which includes a missile and a launcher for launching the missile to a target. The throats for directing exiting sustainer motor propellant gases are aligned so that the gas thrust vectors are near the center of gravity. These throats and vectors are also forward of the missile center of pressure to give the resultant effect of pulling the missile rather than pushing it and hence improves the flight stability of very small missiles. The ignition of both the sustainer motor and the booster motor is accomplished by extending an ignition explosive cord through both motors for the ignition thereof.

United States Patent 1191 1111 3,807,275

Betts Apr. 30, 1974 1 MINIATURE MISSILE SYSTEM 3,401,634 9/1968 Martin et al... 102/497 [75] entor obert E- etts, Hu tsville, Ala. 3,326,128 6/1967 Choate.....- 89/1.818 X [73] Assignee: The United States of America as FOREIGN PATENTS R fAPPUCATIONS represented by the Secremry of the 516,818 1/1940 Great Bntam (SO/35.6 RS Army, Washington, DC. Primary ExaminerSamuel W. Engle [22] filed: 1972 Attorney, Agent, or Firm-Edward J. Kelly; Herbert [21] Appl. No; 295,786 Ber]; Charles R. Carter [52] US. Cl 89/1813, 89/1.8l6, 102/497, ABSTRACT 60/256 A miniature missile system which includes a missile [51] Int. Cl. F41f 3/04, F42b 13/28 and a launcher f launching the missile to a target Fleld of Search 60/256, RS; The throats for directing exiting sustainer motor pro- 102019-3493; 89/1-816 1-813 pellant gases are aligned so that the gas thrust vectors are near the center of gravity. These throats and vec- [56] References Cited tors are also forward of the missile center of pressure UNITED STATES PATENTS to give the resultant effect of pulling the missile rather 2,500,117 3/1950 Chandler 60/201 than Pushing it and hence improves the flight Stability 102 493 of very small missiles. The ignition of both the sus-' 102/49.7 tainer motor and the booster motor is accomplished 2,545,496 3/1951 Short 7 by extending an ignition explosive cord through both 3,273,337 9/1966 Bolieau... 102/497 x motors f the ignition thereog 3,702,090 11/1972 Hoard 89/].816 X 3,439,613 '4/1969 Thomanek 102/493 2 Claims, 4 Drawing Figures 2,503,271 4/1950 Hickman..... 3,007,410 11/1961 Blacker...

PMKNIEDmso 1914 3307- 275 SHEET 1 BF 2 FIG. l

FIG. 2

LOCUS 0F THRUST VECTORS ace. CENTER OF (PRESSURE CONDITION I CONDITION 1:

LOCUS MAY/ LOCUS OF THRUST c? BE FWD. OF 0.0.

FIG. 3

alas-(L215 PATENTEU R 0 I974 SHEU 2 BF 2 MINIATURE MISSILE SYSTEM BACKGROUND OF THE INVENTION This invention relates to the field of missiles. Two major problems exist when using very small missiles having a' length of approximately two inches. One prob- The present invention has provided a solution to the inaccuracy of flight problem by utilizing both a booster motor and a sustainer motor in the missile. The sustainer motor throats are positioned to align the gas thrust vectors exiting therefrom through the center of gravity behind but near to CO. or forward and near the CG. This arrangement allows the throats and thrust v vectors to always be forward of the center of pressure BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is 'a sectional view showing a missile in a launching tube.

FIG.'-2 is a sectional view showing a modification of the sustainer motor ignition.

FIG. 3 is a chart showing the locus of thrust vectors.

FIG. 4 shows a plurality of missiles stacked in a container.'

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1, reference numeral indicates a guidance tube used in launching a missile 12. The missile includes a nose 14, a booster motor 16 and a sustainer motor 18. A plurality of fins 20 are attached to the booster motor for guidance purposes. Each fin has a tip 23 at its outward extremity and the tips mate with the interior diameter of the tube to prevent sideward reaction of the missile when fixed. Motor 16 includes a propellant 24 which when ignited provides the initial thrust for the motor. Vanes 26 are fixed inside in the exit cone 28 of the booster motor for inducing spin to the missile when acted on by the exiting booster motor thrust gases. As an alternative the fins 20 could be placed in a canted position with respect to the longitudinal axis of the missile and aerodynamically acted upon to provide 'missilespin. A wall 30 separates the booster motor from the sustainer motor and is considered to be a transfer point in the ignitiontrain between the two motors. The total sustainer motor thrust area is a combination of the area of orifice 32-plus the area of exit throats 34. The area of orifice 32 is considerably smaller as compared to the total sustainer motor thrust area; therefore a larger percentage of the gases exit throats 34. When sustainer propellant 36 is ignited it provides thrust to the missile to sustain it in flight. The thrust exiting the sustainer motor is at a lower level than the thrust exiting the booster motor. A mild detonating fuse 38 extends through booster motor 16,-orifice 32 and into the sustainer motor. When activated by an ignition impulse the fuse ignites the booster propellant and then the sustainer propellant. An alternative means for igniting the sustainer propellant is shown in FIG. 2. In this system a precussion primer 40 is fitted into orifice 32 and the fuse 38 butts the primer. The ignition impulse is transferred by the fuse to the primer and thus to the sustainer propellant when activated by the primer.

The throats 34 are located in the missile nose in such a manner that the thrust vectors of the exiting sustainer motor gases are aligned near the center of gravity. That is these vectors may be behind but near or forward but near the center of gravity. Such an arrangement locates the throats and thrust vectors so that they are always forward of the center of pressure. The thrust provided by the burning gases of the sustainer motor exits the motor through throats 34 and orifice 32, when present. However more thrust is generated by the gases exiting throats 34 than that exiting orifice 32 and the net effect is that the missile is pulled in flight rather than pushed. As shown in condition I of FIG. 3, the center of gravity is bracketed between the center of pressure and close to the locus of the thrust vectors. In condition II the locus of thrust vectors is shown as moving toward the center of gravity as the sustainer propellant burns. Thus inaccuracy of small missile flight has been solved by using both a booster motor and a sustainer motor in such a manner that the missile is subjected to a pulling effect rather than a pushing effect.

FIG. 4 shows a plurality of missiles and launchers stacked side by side in a container 42 and placed on a launcher 43. A plate 44 fits inside the bottom of the container and the plate is coated with strips of explosive or pyrotechnics 46. Each missile is loaded into the container with its fuse 38 abutting against explosive 46. Thus the ignition train is from a source (not shown) to explosive 46 and then to fuses 38 and all the rockets leave the container 42 substantially at the same time.

I claim:

1. A missile system including a missile and a launcher for launching the missile to a target, said missile comprising: a booster motor having a propellant therein for providing initial thrust to said missile, a cone disposed in said motor to provide an exit for said thrust from the motor; means for inducing spin to said missile, said spin inducing means including fins fixed in a canted position to the exterior of the missile for aerodynamically causing the missile to spin; a sustainer motor having a thrust producing propellant therein; a wall separating said motors, said wall being provided with an orifice; means for igniting the propellant in said motors, said propellant ignitingmeans including a detonating fuse extending through said booster motor, said orifice and said sustainer motor; and a missile nose provided with exit throats being located at the junction of said missile nose and said sustainer motor for directing propellant gases from said sustainer motor, said throats aligning the thrust vectors of the sustainer motor gases near the center of gravity and forward of the missile center of gravity and forward of the missile center of pressure to pull said missile in flight.

2. A missile system including a missile and a launcher for launching the missile to a target, said missile comprising: a booster motor having a propellant therein for providing initial thrust to said missile, a cone disposed in said motor to provide an exit for said thrust from the motor; means for inducing spin to said missile, said spin inducing means including fins fixed in a canted position to the exterior of the missile for aerodynamically causing the missile to spin; a sustainer motor having a thrust producing propellant therein; a wall separating said pressure to pull said missile in flight. 

1. A missile system including a missile and a launcher for launching the missile to a target, said missile comprising: a booster motor having a propellant therein for providing initial thrust to said missile, a cone disposed in said motor to provide an exit for said thrust from the motor; means for inducing spin to said missile, said spin inducing means including fins fixed in a canted position to the exterior of the missile for aerodynamically causing the missile to spin; a sustainer motor having a thrust producing propellant therein; a wall separating said motors, said wall being provided with an orifice; means for igniting the propellant in said motors, said propellant igniting means including a detonating fuse extending through said booster motor, said orifice and said sustainer motor; and a missile nose provided with exit throats being located at the junction of said missile nose and said sustainer motor for directing propellant gases from said sustainer motor, sAid throats aligning the thrust vectors of the sustainer motor gases near the center of gravity and forward of the missile center of gravity and forward of the missile center of pressure to pull said missile in flight.
 2. A missile system including a missile and a launcher for launching the missile to a target, said missile comprising: a booster motor having a propellant therein for providing initial thrust to said missile, a cone disposed in said motor to provide an exit for said thrust from the motor; means for inducing spin to said missile, said spin inducing means including fins fixed in a canted position to the exterior of the missile for aerodynamically causing the missile to spin; a sustainer motor having a thrust producing propellant therein; a wall separating said motors, said wall being provided with an orifice; means for igniting the propellant in said motors, said propellant igniting means having a detonating fuse extending through said booster motor and a precussion primer disposed in said orifice, said fuse abutting said primer and activating said primer when the fuse is ignited; and a missile nose provided with exit throats for directing propellant gases from said sustainer motor, said throats aligning the thrust vectors of the sustainer motor gases near the center of gravity and forward of the missile center of gravity and forward of the missile center of pressure to pull said missile in flight. 